I posted this in other forums.. so want to make sure if anyone is going through this they can have someone else's perspective on what they are going through. Most searches have additional lights/codes appear with the Terrain Management System (TMS) fault (wrench light). I only have the TMS light. Turns out it could just be a low voltage issue.. fingers crossed.
Where to begin.. EcoHell has 45494 miles on her. I drove from NY to FL and arrived on Monday (7/12/21) with no issues. I get back in EcoHell on Tuesday around 3pm and the wrench light pops up and when stepping on the gas it felt like it was running on 3 cylinders, until around 2000 rpms and it ran fine. I immediately made a u-turn and returned back to the house. Used my scanner and didn't have any "terrain management system fault" codes. Had an O2 sensor code which I always had, just not enough to set off the Check Engine light (has nothing to do with this particular story, but just mentioning it). When I turn off the engine and open the door, the wrench light will not return unless you start the engine, go forward or reverse and actually press on the gas pedal.
Wednesday - I called the nearest Ford Dealership to setup an appointment. They were very accommodating, since I was visiting from NY. I called AAA to discuss having EcoHell flatbedded to the dealership. Everything is planned for Thursday. Since EcoHell is going in for service, I disconnect and clean her out.. I disconnected my ICOM radio (ham radio) and internet node (using the inverter with the 110 plug in). I have a dash cam (front and rear) as well. I then start EcoHell. I back out of the carport and when I press on the gas pedal no wrench light. I back up further pressing the gas and still no light. I stop, go forward pressing on the gas pedal and still no wrench light. I then take a small trip around the neighborhood to see how EcoHell is performing. Keep in mind the speed limit is 20mph so the fastest I could go was around 40mph (which was for testing purposes). EcoHell is running like she did before..all is fine. I read other forums that the battery could be the issue.
I wanted to conduct more searches and speak to my mechanic in New York about it. On Tuesday (7/19/21), I purchased a new battery, installed it and tested it immediately. I attempt to back her out of the driveway and the wrench light came on again. However, after a day of having the battery installed, I start her up again, back out of the driveway and no wrench light. After driving her further and no wrench light, I drove to a couple of stores and then drove to a shop where my father has taken his cars too. They will see if the light comes back on. Plus I am getting an oil change.
I am posting this because I never had the wrench light come on. What are your experiences with the Terrain Management System Fault - wrench light?
Bill